Many miniature electronic and optical devices are formed using layers of different materials stacked on each other. These layers are often patterned to produce the devices. Examples of such devices include optical displays in which each pixel is formed in a patterned array, optical waveguide structures for telecommunication devices, and metal-insulator-metal stacks for semiconductor-based devices.
A conventional method for making these devices includes forming one or more layers on a receptor substrate and patterning the layers simultaneously or sequentially to form the device. In many cases, multiple deposition and patterning steps are required to prepare the ultimate device structure. For example, the preparation of optical displays may require the separate formation of red, green, and blue pixels. Although some layers may be commonly deposited for each of these types of pixels, at least some layers must be separately formed and often separately patterned. Patterning of the layers is often performed by photolithographic techniques that include, for example, covering a layer with a photoresist, patterning the photoresist using a mask, removing a portion of the photoresist to expose the underlying layer according to the pattern, and then etching the exposed layer.
In some applications, it may be difficult or impractical to produce devices using conventional photolithographic patterning. For example, the number of patterning steps may be too large for practical manufacture of the device. In addition, wet processing steps in conventional photolithographic patterning may adversely affect integrity, interfacial characteristics, and/or electrical or optical properties of the previously deposited layers. It is conceivable that many potentially advantageous device constructions, designs, layouts, and materials are impractical because of the limitations of conventional photolithographic patterning. There is a need for new methods of forming these devices with a reduced number of processing steps, particularly wet processing steps. In at least some instances, this may allow for the construction of devices with more reliability and more complexity.